Street sweeper with dust control

ABSTRACT

Street sweeper having dust control from two or more cleaning heads with one air source where one fan provides vacuum for a centrally located rotating broom which is surrounded by a vacuumized chamber and for a gutter broom which is surrounded by a vacuumized chamber. A plenum having a unique valving system and a filter shaker mechanism provides for filter cleaning and for a dirt and debris path from the plenum to a hopper bottom during filter cleaning.

CROSS REFERENCES TO RELATED APPLICATIONS

None.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to a street sweeper, and moreparticularly, to dust control from two or more cleaning heads with oneair source.

2. Description of the Prior Art

Prior art dust control systems for road sweepers frequently include theuse of water which wets the debris and dirt on the road surface toprevent dust from becoming airborne during the sweeping process. In suchsystems, water must be provided at various sweeper locations, such as,but not limited to, the main rotary broom and the gutter brooms. Watersystems often just wet down debris and dirt whereby the wetted debrisand dirt may still reside on the wetted roadway after sweeping ratherthan having been carried into the conveyor or hopper. The use of vacuumsystems instead of water systems to carry off generated airborne dust isoften desirable in that no wetted debris or dirt is presented to be leftbehind after sweeping. Vacuum systems generally use a separate dedicatedfan to draw dust from the region of the main rotary broom and a separatededicated fan to draw dust from the region of the gutter brooms. The useof separate and dedicated fans results in excessive space being occupiedand adds expense to the fabrication processes. The use of separate anddedicated fans can also produce a flow problem where the vacuum producedby one fan may interfere or conflict with the vacuum of another fan whenentering a common chamber or plenum.

Another problem encountered in dry dust control systems is that ofclogging of a filter located prior to the fan. Filter clogging isdetrimental to the removal of dust before discharging air from the fanto the atmosphere and can slow and hinder the vacuuming processsignificantly. Cleaning or exchanging a filter can be a laborious andtime-consuming process resulting in poor overall efficiency.

SUMMARY OF THE INVENTION

The general purpose of the present invention is to provide a streetsweeper having dust control from two or more cleaning heads with one airvacuum source in a road sweeper, as well as a dust filtration systemwhich can be readily cleaned on site without the removal of filtrationcomponents and without other extraordinary measures. The presentinvention can be incorporated for use along a substantially planarsurface, such as a road where the term road can mean any surface withina manufacturing facility, such as a tiled or concrete paved surface orthe like, and can also be utilized along a common roadway. In thepresent invention, a single fan is mounted to a plenum in the upperregion of a truck-mounted hopper to provide vacuum for dust control. Afilter mechanism and a filter shaker mechanism mount just below the fanin the upper region of the plenum. The bottom of the plenum includes anorificed plenum array having a plurality of automatic flexible airflowoperated flap valves which are closed during the sweeping operation toseal the bottom of the plenum.

Inlet passageways or ports are located about the plenum for vacuumizedairflow into the plenum for subsequent filtration. Filtration can be anyporous filter and centrifugal system or the like. One such passageway, alower inlet port, is located on and extends from the bottom of theplenum and connects to a gutter broom air conduit which communicateswith a gutter cleaning head including a cleaning head shroud forming acleaning head chamber capable of being vacuumized and being locatedbeneath the sweeper truck chassis for vacuumized removal of airbornedust. Additionally, appropriately sized upper inlet ports located on theupper and rear side of the plenum communicate to the interior of thehopper and to a connected conveyor housing or conduit and thence to anelongated cleaning head including an elongated cleaning head shroudforming an elongated cleaning head chamber which can be vacuumized whichis located about the main rotary broom for vacuumized removal ofairborne dust.

Vacuum integrity of the plenum is automatically maintained duringsweeping operations by the plurality of automatic flexible airflowoperated flap valves which are influenced by vacuum (airflow) and urgedto the closed position. Subsequent to the sweeping operation and whencleaning of the filter mechanism is required, power to the fan isstopped, thereby influencing the vacuum integrity of the plenum causingthe cessation of vacuum in the plenum and the areas or regions withwhich the vacuum communicates. The filter shaker mechanism is thenactuated at this time to expel dust and small debris from the filtermechanism which descends gravitationally to the region in the plenumjust below the filter to pass through the flap valves which have beengravitationally opened due to the cessation of vacuum or airflow withinthe plenum. The dust and debris passes through the open flap valves intothe lower regions of the hopper. The filter shaker mechanism includes anelongated cam which repeatedly causes gradual vertical upward movementof a rod encased in each of the lower folds of each filter tomomentarily deform each filter fold followed by sudden cam disengagementto cause rapid downward movement of the rods, whereby the force of whichcauses vigorous snapping retensioning of the folds to expel dustparticles therefrom.

According to one or more embodiments of the present invention, there isprovided a street sweeper having dust control from two or more cleaningheads with one air source including a hopper, a plenum mounted in theupper region of the hopper, a fan mounted to the top of the plenum, afilter mechanism located at the upper region of the plenum in closeproximity to and below the fan including fixed rods extending across thetop of the plenum being captured by and extending through the upperregion filter folds and positionable rods extending across the lowerregion of the plenum being captured by and extending through the lowerregion filter folds, cutouts in the lower region of the filter foldswhich expose a portion of each of the positionable rods, a filter shakermechanism having a motorized cam extending perpendicularly to thepositionable rods for contacting the exposed portion of each of thepositionable rods, a plenum bottom having a plurality of orifices in anarray, a plurality a flexible valves which align to the bottom of theplurality of arrayed orifices, a duct extending downwardly from a lowerinlet port at the plenum bottom and connecting to a gutter cleaning headsurrounding opposing gutter broom assemblies, and inlet ports in theupper and rear portion of the plenum. Other shown items which relate tothe use of the present invention include a conveyor mechanism containedin a conveyor housing or conduit extending between the upper region ofthe hopper and a vacuumized chamber at the rear of a road sweeper truck,and a truck-mounted scissors jack which supports the hopper andcontained plenum.

One significant aspect and feature of the present invention is a streetsweeper having dust control from two or more cleaning heads with one airsource.

Another significant aspect and feature of the present invention is afilter shaker mechanism which cleans a filter in a filter mechanismwithout removal of the filter from the sweeper truck.

Still another significant aspect and feature of the present invention isa plurality of fixed rods located in the upper region of the filterfolds and a plurality of partially exposed positionable rods located andcaptured in the lower region of the filter folds.

Yet another significant aspect and feature of the present invention is afilter shaker mechanism having a cam which urges a plurality ofpartially exposed positionable rods captured in the lower region of thefilter folds upwardly to cause upward distortion, displacement anddistension of the filter folds followed by a sudden disengagement fromintimate cam contact thereby allowing the filter folds to snappingly andjarringly return to the unactuated position to release and shed dustparticles from the surfaces of the filter folds. Such action is repeateduntil cleaning is complete.

A further significant aspect and feature of the present invention is anarray of automatic flexible airflow operated valves co-acting witharrayed orifices in a plenum bottom. When air is flowing, each valve ispositioned by airflow against the plenum bottom to seal the bottom ofthe plenum. When air is not flowing, each valve relaxes andgravitationally repositions from intimate contact with the plenum bottomto break the seal with the bottom of the plenum.

Having thus described embodiments of the present invention and mentionedsome significant aspects and features thereof, it is the principalobject of the present invention to provide a street sweeper having dustcontrol from two or more cleaning heads with one air source, and whichalso provides for filter cleaning.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects of the present invention and many of the attendantadvantages of the present invention will be readily appreciated as thesame becomes better understood by reference to the following detaileddescription when considered in connection with the accompanyingdrawings, in which like reference numerals designate like partsthroughout the figures thereof and wherein:

FIG. 1 illustrates a cutaway overview of the street sweeper having dustcontrol from two or more cleaning heads with one air source, the presentinvention;

FIG. 2 illustrates a cutaway side view of the street sweeper;

FIG. 3 illustrates an exploded view of the filter, certain components ofthe plenum, the filter shaker mechanism and other associated componentswhich, in part, provide for dust control from two or more cleaning headswith one air source for the street sweeper;

FIG. 4 illustrates an assembled view of the filter mechanism, certaincomponents of the plenum, the filter shaker mechanism and otherassociated components which, in part, provide for dust control from twoor more cleaning heads with one air source for the street sweeper;

FIG. 5 illustrates a cutaway view of the hopper, the filter mechanism,and the plenum along with other components associated with those parts,and also illustrates the multi-component gutter broom duct;

FIG. 6 illustrates a cutaway front view of the hopper revealing thefilter mechanism, the plenum, and other components associated andutilized therewith during the sweeping mode;

FIG. 7 illustrates a cutaway front view of the hopper revealing thefilter mechanism, the plenum, and other components associated andutilized therewith during the filter mechanism cleaning mode duringwhich the eccentric cam of the filter shaker mechanism is actuated;

FIG. 8 illustrates a view of the hopper and associated components forthe street sweeper in the tipping position at the level of a truckchassis;

FIG. 9 illustrates a view of the hopper and associated components forthe street sweeper in the tipping position above the level of a truckchassis; and,

FIG. 10 is a simplified schematic of airflow through the componentsproviding dust control from two or more cleaning heads for the streetsweeper.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a cutaway overview of the street sweeper 10, thepresent invention, having dust control from two or more cleaning headswith one air source. Major components and other components complementaryto the street sweeper are mounted to and secured to the frame or chassis13 (FIG. 2) of a truck 12 or are mounted elsewhere at other locationsabout the invention. Major components of the invention include a vacuumsource, such as a fan 26, a fan shroud 27, a hopper 14, a plenum 34, anorificed plenum array 35, a plurality of one-piece flap valves 37 a-37 n(FIG. 3), a filter mechanism 30 including a filter 33 and othercomponents which provides for support and function thereof, and a filtershaker mechanism 31 (FIG. 2), the majority of which connectassociatively with other major members and components of the streetsweeper 10 including a gutter broom assembly 52 having a right gutterbroom 53 and a left gutter broom (not shown), a gutter cleaning head 47including a cleaning head shroud 49 forming a gutter cleaning headchamber 54 which is capable of being vacuumized, a vertically orientedgutter broom duct or air conduit 56 between the gutter cleaning headchamber 54 and the hopper 14, a conveyor mechanism 16, a conveyorhousing or conduit 18, a rotary broom 20, an elongated cleaning head 22including an elongated cleaning head shroud 29 and elongated cleaninghead chamber 41 which is capable of being vacuumized and whichcommunicates with the hopper 14, the members of which are arranged andmounted to the chassis 13 of the truck 12 or other frameworks. Therearwardly extending framework 21 and an opposing like framework (notshown) mount and secure to the chassis 13 of the truck 12 to accommodatea portion of the components of the invention or associated components. Asuperstructure framework 23 including a plurality of framework members23 a-23 n is shown partially and generally in dashed lines extendingupwardly and forwardly from the framework 21 to serve as structure formounting of fixed panels or access panels, doors or other devices asrequired. An optional water tank 58 is installed for wet sweeping, ifrequired.

The hopper 14 secures to the truck chassis 13 via a scissors jackassembly 24 which mounts to the truck chassis 13 via a scissors jackmounting frame 25. The plenum 34 and associated plenum panels (see alsoFIG. 2) is located at the upper region of the hopper 14 and houses andsupports the filter mechanism 30. The fan 26, a vacuum source, isattached to a hopper top panel 32 or, alternatively, may be mountedwithin the plenum 34, above the plenum 34, or external to the plenum 34via an air conduit, and has an exhaust port 28 which is open to andwhich communicates through the filter mechanism 30 in part with theinterior of the hopper 14, in part with the gutter cleaning head 47, andin part with the elongated cleaning head 22 at the rear of the streetsweeper 10. The top of the filter mechanism 30 aligns closely to thebottom surface of the hopper top panel 32 in close proximity to thebottom of the fan 26. The orificed plenum array 35 orients to and facesthe lower interior of the hopper 14. The one-piece flap valves 37 a-37 n(FIG. 3) in the orificed plenum array 35 close during sweepingoperations and open during cleaning cycles as dictated by airflow. Thefan 26 communicates via the filter mechanism 30 and the gutter broomduct or air conduit 56 to the gutter cleaning head 47. Inlet ports 66and 68 (FIG. 3), which are screened and which are located in the upperand rear portion of the plenum 34, communicate with the interior of thehopper 14 and subsequently with the conveyor housing or conduit 18 andelongated cleaning head 22 at the rear of the street sweeper 10. Areceiver duct 36 mounts to the hopper top panel 32 to communicate withthe interior of the hopper 14 and to sealingly connect with the elevatedend of conveyor housing or conduit 18. A flexible seal 38 and opposingflexible side seals 39 and 39 a and other seals located at the upper endof the conveyor housing or conduit 18 seal against components located atthe inlet of the receiver duct 36, as shown in FIG. 2. An angled channel42 is located in a vertically oriented hopper rear panel 44 foraccommodation of the upper end of the conveyor mechanism 16. Lower andupper access doors 46 and 48 for emptying of the hopper 14 are locatedon an outwardly facing and vertically oriented right hopper panel 50 ofthe hopper 14. The hopper 14 also includes a left hopper panel 51 and aconfigured front hopper panel 55, both shown in FIG. 5.

FIG. 2 illustrates a cutaway side view of the street sweeper 10.Illustrated in particular is the hopper 14, the fan 26, the plenum 34,the filter mechanism 30, the filter shaker mechanism 31, the orificedplenum array 35, the gutter broom duct or air conduit 56 and the guttercleaning head 47 which connect associatively with other members andcomponents of the street sweeper 10. Filtration components, such as, butnot limited to, the filter mechanism 30, the filter shaker mechanism 31,and the orificed plenum array 35, may be positioned within the plenum34, as shown, or may be positioned above the plenum 34, or external tothe plenum 34 via an air conduit.

FIG. 3 illustrates an exploded view, and FIG. 4 illustrates an assembledview of the filter mechanism 30, certain components of the plenum 34,the filter shaker mechanism 31, and other associated components which,in part, comprise the street sweeper 10, the present invention. Theplenum 34 is formed in part by the illustrated components, as well asother components including portions of sidewalls of the hopper 14. Theillustrated components of the plenum 34 include a multi-angled andconfigured rear plenum panel 60 having planar regions 60 a, 60 b, 60 cand 60 d, an angled and configured front plenum panel 62 having planarregions 62 a and 62 b, and an angled and configured right plenum panel64 having planar regions 64 a and 64 b. Inlet ports 66 and 68 arelocated along and about the planar region 60 b of the rear plenum panel60.

The orificed plenum array 35 includes a plurality of valve orifices 70a-70 n bordered by an angled front planar region 35 a and an angled rearplanar region 35 b, as well as a lower inlet port 72 at one corner ofthe orificed plenum array 35. The angled front planar region 35 a andthe angled rear planar region 35 b of the orificed plenum array 35 alignto and extend between the angled planar region 62 b of the front plenumpanel 62 and the angled planar region 60 d of the rear plenum panel 60,respectively. A plurality of inverted angle stock members 74 a-74 nalign between the front planar region 35 a and the rear planar region 35b of the orificed plenum array 35 to longitudinally separate the valveorifices 70 a-70 n and to offer support of the valve orifices 70 a-70 n.Each of the sides of the angle stock members 74 a-74 n presents a 45_(E)angled surface with respect to the valve orifices 70 a-70 n. The 45_(E)angle surfaces of the angle stock members 74 a-74 n serve to assist andchannel dust and small debris through the valve orifices 70 a-70 nduring the filter cleaning process, as later described in detail. Aplurality of flap valves 37 a-37 n align to and secure to the undersideof the orificed plenum array 35. The first flap valve 37 a aligns to thefirst row of valve orifices 70 a-70 n containing valve orifices 70 a-70e and each of the remaining flap valves 37 b-37 n aligns successively tothe other rows of valve orifices 70 a-70 n. Identically constructed stoprods 78 a and 78 b secure to the underside of the orificed plenum array35 by like brackets 80.

Filter 33 of the filter mechanism 30, the components of which are nowdescribed herein, suspends from a filter hanger 82 to align within theplenum 34. The filter hanger 82 is shown positioned above the filter 30for purposes of illustration. The filter hanger 82 includes a four-sidedframe 84 and a plurality of parallel rods 86 a-86 n mounted within theframe 84. The filter 33 is fashioned in a continuous manner wave-likeconfiguration having a plurality of top folds 88 a-88 n and a pluralityof bottom folds 90 a-90 n extending transversely. A flexible perimeterflap 92 is attached to the left and right edges of the top folds 88 a-88n, as well as transversely to the top of the top folds 88 a and 88 n.During assembly, the filter 30 is lowered through and suspended by thefilter hanger 82. During lowering the bottom folds 90 a-90 n are fittedbetween the parallel rods 86 a-86 n of the filter hanger 82 and thenfurther lowered until the top folds 88 a-88 n engage the rods 86 a-86 nin the position shown in FIG. 4. The perimeter flap 92 is then foldedover and about the surrounding frame 84 and secured thereto. Pockets 94a-94 n at the bottom of each bottom fold 90 a-90 n are formed bystitching to capturingly accommodate a plurality of rods 96 a-96 n shownin foreshortened manner. The rods 96 a-96 n extend beyond the length ofthe pockets 94 a-94 n at both ends. A right rod keeper plate 98 having aplurality of holes 98 a-98 n aligns over the right end of the rods 96a-96 n. A left rod keeper plate 100 having a plurality of holes 100a-100 n aligns over the left end of the rods 96 a-96 n. Suitable devicessuch as cotter pins extending through the opposing ends of the rods 96a-96 n ensure alignment and placement of the rods 96 a-96 n in the holes98 a-98 n and 100 a-100 n, as well as ensure containment in the pockets94 a-94 n. A plurality of cutouts 104 a-104 n are included at the bottomof each bottom fold 90 a-90 n to expose the rods 96 a-96 n.

A filter shaker mechanism 31 includes an eccentric cam 106, a motor 108,preferably hydraulic, and bearings 110 and 112. The bearing 110 supportsone end of the eccentric cam 106 and the bearing 112 supports the otherend of the eccentric cam 106. Motor 108 provides for rapid rotation ofthe eccentric cam 106 about its longitudinal axis. The eccentric cam 106extends through holes 116 and 118 in the front plenum panel 62 and therear plenum panel 60, respectively, and aligns in near proximity to therods 96 a-96 n which are exposed through the cutouts 104 a-104 n in thebottom folds 90 a-90 n of the filter 33.

FIG. 5 illustrates a cutaway view of the hopper 14, the filter mechanism30, and the plenum 34 along with other components associated with theseparts. Also illustrated is the multi-component gutter broom duct or airconduit 56 which includes a main section 56 a, a top subsection 56 bpermanently telescoped into the main section 56 a, a seal 61 secured tothe bottom 57 of the hopper 14 in alignment to the telescoped topsubsection 56 b, a mid subsection 56 c the top portion of which alignsto the bottom portion of the telescoped top subsection 56 b and to theseal 61, a seal 63 aligned to the bottom of the mid subsection 56 c, anda bottom subsection 56 d the top part of which mates to the seal 63 andthe bottom part of which secures to the gutter cleaning head chamber 54(FIG. 1). Tipping of the hopper 14 for unloading can utilize varioussections of the gutter broom duct or air conduit 56, as later describedin relation to FIGS. 8 and 9, dependent on whether the hopper 14 istipped at a low elevation or if the hopper 14 is raised by the scissorsjack assembly 24 for tipping at an elevated position. The structure ofthe plenum 34 includes and is bounded in full or in part by thefollowing major components including the rear plenum panel 60, the frontplenum panel 62, a portion of the right hopper panel 50, the rightplenum panel 64 (FIG. 3), a portion of the left hopper panel 51, theorificed plenum array 35 and attached flap valves 37 a-37 n, and, thehopper top panel 32. Also shown is the close proximity and orientationof the eccentric cam 106 with the plurality of rods 96 a-96 n in thebottom folds 90 a-90 n of the filter 33. It is to be noted that flexibleU-shaped porous and breathable spacers 120 a-120 n (120 a and 120 nshown) are inserted over every other top fold 88 a-88 n of the filter 33and seated between the folds to provide adequate spacing between thevertical portions of adjacent folds and to maintain suitable filtershape.

FIG. 6 illustrates a cutaway front view of the hopper 14 revealing thefilter mechanism 30, the plenum 34, and other components associated andutilized therewith during the sweeping mode. Illustrated in particularis the relationship of the flap valves 37 a-37 n to the respective valveorifices 70 a-70 n. A plurality of fasteners 119 a-119 n secure the flapvalves 37 a-37 n to the respective valve orifices 70 a-70 n. Suctionfrom the fan 26 creates a low pressure region in the upper region of theplenum 34 thereby causing the flap valves 37 a-37 n to be urged towardand against the valve orifices 70 a-70 n, thereby sealing the bottom ofthe plenum 34 at the orificed plenum array 35 to maintain vacuumintegrity of the plenum 34 during sweeping. Also shown is the eccentriccam 106 in the un-actuated position in close proximity to the exposedportions of the rods 96 a-96 n in cutouts 104 a-104 n whereby the regionbetween the top folds 88 a-88 n and bottom folds 90 a-90 n of the filter33 are unaffected and fully extended in a downward direction owingdirectly to the weight of the rods 96 a-96 n.

The hopper 14 and associated plenum and filter components are capable ofbeing tipped to discharge trash, debris and dust accumulated in thesweeping process. Pivot supports 134 a and 134 b attached to the lowerregions of the hopper 14 allow for such tipping such as by componentscontained in the scissors jack assembly 24 (not shown). The pivotablelower access door 46, controlled by an actuating cylinder 136, is heldretracted by the retracted actuating cylinder 136 which is shown in theretracted position. The retracted lower access door 46 engages thepivotable upper access door 48 to maintain the upper access door 48 in aclosed position. During tipping, the actuating cylinder 136 is extendedto open the lower access door 46 which then ceases to engage the upperaccess door 48, thereby allowing full opening of one side of the hopper14 for emptying.

FIG. 7 illustrates a cutaway front view of the hopper 14 revealing thefilter mechanism 30, the plenum 34, and other components associated andutilized therewith during the filter cleaning mode during which theeccentric cam 106 of the filter shaker mechanism 31 is actuated.Illustrated in particular is the relationship of the flap valves 37 a-37n to the respective valve orifices 70 a-70 n. Suction from the fan 26 isdiscontinued thereby creating regions of equal pressure region in theplenum 34 and in the lower region of the hopper 14, thereby causingrelaxation of the flap valves 37 a-37 n to be gravitationally urged fromintimate contact with the valve orifices 70 a-70 n, thereby opening thebottom of the plenum 34 at the orificed plenum array 35 to allowcommunication through the valve orifices 70 a-70 n. Also shown is theeccentric cam 106 in the actuated position in vigorous repeated contactwith the exposed portions of the rods 96 a-96 n in cutouts 104 a-104 nwhereby the folds of the filter 33 are agitated to release dust andother small debris particles.

FIG. 8 illustrates a view of the hopper 14 and associated components ofthe street sweeper 10 in the tipping position at the level of the truckchassis 13 where dirt and debris is emptied from the hopper 14 thoughthe access doors 46 and 48. Tipping the hopper 14 can be accomplished ata non-elevated hopper level, such as at the level of the truck chassis13, or a scissors jack 138 (FIG. 9) can be actuated and the hopper 14can be tipped at levels above that of the truck chassis 13. In eithercase, an actuating cylinder 140 is actuated to effect hopper 14 tipping,as well as actuating cylinder 136, which allows opening of the lower andupper access doors 46 and 48, as previously described. During tipping ofthe hopper 14 at truck chassis 13 level, the main section 56 a and thetelescoped top subsection 56 b separate from engagement with the upperportion of the mid subsection 56 c.

FIG. 9 illustrates a view of the hopper 14 and associated components ofthe street sweeper 10 in the tipping position above the level of thetruck chassis 13 where dirt and debris is emptied from the hopper 14through access doors 46 and 48 at a position elevated by the scissorsjack 138 and by one or more actuating cylinders 142 to a level above thetruck chassis 13. During tipping of the hopper 14 above the truckchassis 13 level, the main section 56 a, the telescoped top subsection56 b, and the mid subsection 56 c separate from engagement with theupper portion of the bottom subsection 56 d. Alignment of gutter broomduct components 56 a-56 d, as previously described, accommodatesgeometrical conflicts with various support structures.

FIG. 10 is a simplified schematic of airflow through the central regionof the street sweeper 10, where all numerals correspond to thoseelements previously described. Shown in particular is the flow ofdust-laden air 130 through the inlet ports 66 and 68 into the plenum 34and the flow of dust-laden air 131 through the lower inlet port 72 wherethe flows are combined and drawn through the filter mechanism 30 andthrough the fan 26 to exit as a combined flow of clean air 132 and 133.The proper and balanced volume or intensity of airflow through theelongated cleaning head 22 and through the gutter cleaning head chamber54 (FIG. 1) is influenced largely by the sizes of the inlet ports 66 and68 in relation to the size of the lower inlet port 72. For purposes ofillustration and example, half of the flow could transit through theinlet ports 66 and 68 and the other half could flow through the lowerinlet port 72. If increased vacuum is desired through the inlet ports 66and 68 because of vacuum demands at the elongated cleaning head 22, thesize of the lower inlet port 72, the opposing orifice, could be adjusteddownwardly to decrease the flow through the lower inlet port 72 to allowan increase of flow through the inlet ports 66 and 68. Conversely, ifincreased vacuum is desired through the lower inlet port 72 because ofvacuum demands at the gutter cleaning head chamber 54, the sizes of theinlet ports 66 and 68, the opposing orifices, could be adjusteddownwardly to decrease the flow through the inlet ports 66 and 68 toallow an increase of flow through the lower inlet port 72.

Mode of Operation

FIGS. 5-10 illustrate the mode of operation of the street sweeper 10with respect to sweeping and cleaning of dust-laden air 130. FIG. 5illustrates the flow of dust-laden air 130 from the elongated cleaninghead 22 via the conveyor housing or conduit 18 (FIG. 2). The fan 26creates an area of low pressure within the plenum 34 wherein part of theflow created by the low pressure communicates through the inlet ports 66and 68 to draw the dust-laden air 130 through the inlet ports 66 and 68.The balance of the flow draws dust-laden air 131 from the guttercleaning head 47 via the gutter broom duct or air conduit 56 and thelower inlet port 72, as shown in FIG. 6. The dust-laden air 130 then isdrawn through the filter 33 for filtration of dust and small debris. Thefan 26 then expels the clean air 132 from the exhaust port 28 directlyto atmosphere without recirculation. The low pressure created by the fan26 also provides a pressure differential to ensure closure of the flapvalves 37 a-37 n against the valve orifices 70 a-70 n during thesweeping mode to maintain integrity of the plenum 34. FIG. 6 illustratesthe flow of dust-laden air 131 from the gutter cleaning head 47 (FIG. 2)via the gutter broom duct or air conduit 56 and the lower inlet port 72.The balance of the low pressure created by the fan 26 in the plenum 34and not communicating through the inlet ports 66 and 68 communicatesthrough the multi-membered gutter broom duct or air conduit 56 to drawthe dust-laden air 131 through the gutter broom duct or air conduit 56and thence through the bottom region of the plenum 34 through the lowerinlet port 72 to be then drawn through the filter 33 and through fan 26to be expelled directly as clean air 133 to the atmosphere. FIG. 7illustrates the cleaning mode of operation for the street sweeper 10.Rotation of the fan 26 is stopped to accomplish the cleaning of thefilter 33 of the filter mechanism 30 followed by application of suitablepower to the motor 108 to cause rapid rotation of the eccentric cam 106.The rotating eccentric cam 106 contacts the portions of the rods 96 a-96n exposed in the cutouts 104 a-104 n of the filter 33 to cause vigorousand repeated vertical or near vertical displacement of the rods 96 a-96n. Vertical displacement of the rods 96 a-96 n, which are contained inthe pockets 94 a-94 n, carries the bottom folds 90 a-90 n of the filter33 upwardly in unison with rod 96 a-96 n displacement. Just aftermaximum vertical displacement of the rods 96 a-96 n and the bottom folds90 a-90 n, the eccentric cam 106 rotatingly and suddenly disengages fromintimate contact with and terminates immediate contactual influence withthe rods 96 a-96 n, thereby allowing gravitational forces to cause therods 96 a-96 n, being of sufficient weight, to descend forcefully andrapidly. Such forceful and rapid descent of the rods 96 a-96 n isbrought to a rapid and jarring halt as the folds of the filter 33suddenly retension, thereby causing a jolting and snapping action of thefolds and walls of the filter 33. Repeated jolting and snapping actionjars dust and small debris from the filter 33. During the filtercleaning mode, the flap valves 37 a-37 n are no longer held in positionagainst the valve orifices 70 a-70 n of the orificed plenum array 35 dueto the lack of differential pressure on the opposite sides thereof. Theopen valve orifices 70 a-70 n allow dust and small debris to passtherethrough for collection in the lower regions of the hopper 14. Thedownward travel of the unactuated flap valves 37 a-37 n is limited bythe stop rods 78 a-78 b in order to keep the flap valves 37 a-37 nsufficiently close to the valve orifices 70 a-70 n to ensure vacuumoperation of the flap valve 37 a-37 n to the closed position against thevalve orifices 70 a-70 n upon reactivation of the fan 26 duringsweeping. The hopper 14 can be tipped and emptied, as previouslydescribed in FIGS. 8 and 9.

Although a street sweeper is described, such operating principles andstructures, as described herein, can be applied to sweepers of othersizes, such as a floor sweeper or other sweeping devices, and shall notbe deemed to be limiting to the scope of the invention.

Various modifications can be made to the present invention withoutdeparting from the apparent scope hereof.

1. A road sweeper with dust control for cleaning a surface, the roadsweeper comprising: a. a vacuum source; b. a main road surface cleaninghead in fluid communication with the vacuum source, and having anopening adjacent a surface intended to be cleaned; c. at least a firstgutter cleaning head in fluid communication with the vacuum source, andhaving an opening adjacent a gutter area intended to be cleaned; d. ahopper for collecting dust, dirt, and debris; e. a conveying mechanismin fluid communication with the vacuum source, and in communication withthe road surface cleaning head for transporting dust, dirt, and debrisfrom the main road surface cleaning head to the hopper; and, f. a commonair filtration mechanism for substantially removing airborne dust in airdrawn from the main cleaning head opening and the gutter cleaning headopening by way of the vacuum source.
 2. The road sweeper of claim 1,wherein: a. the vacuum source concurrently establishes, (1) a firstairflow following a first airflow path from the main road surfacecleaning head, through the vacuumized conveying mechanism, and enteringthe hopper, thereby vacuumizing, at least in part, the main road surfacecleaning head, the conveying mechanism, and the hopper; and, (2) asecond airflow following a second airflow path from the gutter cleaninghead for vacuumizing, at least in part, the gutter cleaning head; and,b. the air filtration mechanism is in the path of the first and secondairflow paths for filtering air passing therethrough so that anyairborne dust in the first and second air flow paths is substantiallyblocked.
 3. The road sweeper of claim 1, wherein: a. the main roadsurface cleaning head includes an elongated rotary broom having arotational axis substantially aligned with the road surface; b. thegutter cleaning head includes a rotary broom having an axis of rotationgenerally transverse to the road surface; and, c. the vacuumizedconveying mechanism is a conveyor mechanism for transporting the dirtand debris to the hopper, and where the conveyor mechanism is surroundedat least in part by a vacuumized housing having an open end incommunication with the main road surface cleaning head, and a secondopen end in communication with the hopper.
 4. The road sweeper of claim1, wherein: a. the main road surface cleaning head includes apressurized air inlet and an air outlet whereby debris entrained withand carried along by the air being conducted through the main roadsurface cleaning head exits therefrom through the conveying mechanism;and b. the conveying mechanism is an air conduit for transporting anydirt and debris to the hopper.
 5. The road sweeper of claim 1, furtherincluding an air intake plenum having, a. one or more first inlet portsin communication with an air chamber formed by the hopper; b. at leastone second inlet port in direct communication with the gutter cleaninghead through an air conduit coupled thereto; and c. a plenum air exitport in communication with the vacuum source.
 6. The road sweeper ofclaim 5, wherein: a. the air filtration mechanism is mounted within, atleast in part, the air plenum and includes a mechanism for loosening anydirt therewith to fall with gravity; and b. the air plenum includes anadjustable bottom portion open to the hopper in a first configuration,and substantially closed relative to the hopper in a secondconfiguration, so that any loosened dirt may fall into the hopper whenthe adjustable bottom portion is in the open condition.
 7. The roadsweeper of claim 6, wherein the plenum adjustable bottom portionincludes flap valves operable in a first condition for sealing thebottom portion of the air plenum relative to the hopper, and in a secondcondition for opening the bottom portion open to the hopper.
 8. The roadsweeper of claim 7, wherein the flap valves are automatically operatedby the presence or absence of airflow established by the vacuum source.9. The road sweeper of claim 2, wherein the first and second airflowpaths continue to the outside environment, and the air filtrationmechanism substantially blocks any airborne dust in the first and secondair flow paths from exhausting out to the outside environment.
 10. Theroad sweeper of claim 6, wherein the filtration mechanism includes: a. aporous filter for passing air therethrough and depositing any airbornedust therewith on the filter; and b. a filter shaker mechanism forshaking the collected dust on the porous filter to fall with gravity.11. The road sweeper of claim 6, wherein the filtration mechanismincludes a centrifugal dust collection system for passing airtherethrough and collecting any airborne dust therewith.
 12. A streetsweeper, comprising: a. a framework for mounting to a truck chassis; b.a vacuum source carried by the framework, the vacuum source including aplenum, a vacuum source, a hopper depending from the plenum, a filtermechanism, and an adjustable plenum being sealable in a firstconfiguration and open in a second configuration; c. a first elongatedcleaning head in fluid communication with the vacuum source, the firstelongated cleaning head opening adjacent a roadway surface to be sweptand about a main rotary broom for vacuumized removal of airborne dust,and having a connected conveyor housing providing fluid communicationbetween the first elongated cleaning head and the vacuum source; and, d.a second cleaning head in fluid communication with the vacuum source,the second cleaning head opening adjacent a roadway gutter to be cleanedand about a gutter broom located beneath the sweeper truck chassis forvacuumized removal of airborne dust, and having a connected ductproviding fluid communication between the second cleaning head and thevacuum source.
 13. The dust control system for a street sweeper of claim12, wherein the filter shaker mechanism includes a cam.
 14. The dustcontrol system for a street sweeper of claim 13, wherein the cam lifts arod in contact with the filter.
 15. The dust control system for a streetsweeper of claim 14, wherein the rod lifted by the cam is one of aplurality of positionable rods located at lower folds of the filter. 16.The dust control system for a street sweeper of claim 12, wherein thefilter is held within the plenum by a plurality of fixed rods extendingacross a top region of the plenum during operation of the shakermechanism.
 17. The dust control system for a street sweeper of claim 12,wherein the fan is non-operational during operation of the filter shakermechanism.
 18. The dust control system for a street sweeper of claim 12,wherein the automatic flexible airflow operated flap valves of theorificed plenum array open the bottom of the plenum, in the secondconfiguration, when the fan is non-operational.
 19. The dust controlsystem for a street sweeper of claim 12, wherein the automatic flexibleairflow operated flap valves of the orificed plenum array seal thebottom of the plenum, in the first configuration, when the fan isoperational. 20-24. (canceled)
 25. A street sweeper, comprising: a. aframework for mounting to a truck chassis; b. a vacuum source carried bythe framework; c. a plenum having an adjustable bottom sealing thebottom of the plenum in a first configuration and opening the bottom ofthe plenum in a second configuration; d. a hopper depending from theplenum; e. a filter and filter shaker mechanism mounted in the plenumand below the fan; f. a first elongated cleaning head in fluidcommunication with the vacuum source, the first elongated cleaning headopening adjacent a roadway surface to be swept and about a main rotarybroom for vacuumized removal of airborne dust; g. a connected conveyorconduit providing fluid communication between the first elongatedcleaning head and the vacuum source; and, h. at least one secondcleaning head in fluid communication with the vacuum source, the atleast one second cleaning head opening adjacent a roadway gutter to becleaned and about a gutter broom located beneath the sweeper truckchassis for vacuumized removal of airborne dust, and having a connectedduct providing fluid communication between the second cleaning head andthe vacuum source.